Lulu’s Summer Dress w/ Peek-A-Boo Back

This flowly dress is a beauty with the tone on tone plaid burnout pattern. I have this dress listed as a M, but I cannot find the size anywhere on the dress. So I’m basing that size off all other dresses I wear (size M or 6/8). Measurements taken from dress: 47”l strap to hem 14” waist